Surveying instrument



.2 8 J. l 5 5, l

A T T E N E V i,

Aug. 25, 1925. l

SURVEYING I NSTRUMENT 2 Sheevts-Sheet 1 Sept.. 2. 1924 .Filed J'av 77E/7am, invento/o Patented Aug. 25, 1925.

uNirEos'r Ares PATENT :OFFICE-i; "Jonnvanmra, oiiwajnnanjonropf H sentarme Ins'rnnnnuri .Appleman aieaspamber maze smiley. nam. 'f i To all whom t may concern.'

i Beft known thatI, J OHN VENETTAya citizen. of the United States,` residing at Warren, in the county `of Trumbull and Stateof Ohio, have invented certain newand useful Improvements in a Surveying Instrument, of which the following is a specification.` 1 This. invention relates to @surveying in struments and it consists `inl-the novelfea tures hereinafter described and claimed. An object of the invention istoprovide an instrument which may be easily andconveniently `used for accurately `determining the distance between fixed o jects and the distance at 'which the said objects are `from the point at which the 'instrument is locatedf i f y lVith the above object in view the in strument. comprising la` Acasing-having a table mounted thereon, a compass embedded in the table and Ymeans as for instance a spirit levelforpositioning the casing and table level or horizontal. The table is provided at its edge with a series of .graduations. A shaft is journaled for rotation at the center of the table and a frame is carried by said shaft and is disposed diametrically of the table. Means are provided for turning the shaft. A vertically disposed mirror is carried by the shaft and a series of graduations is carried by the frame and adapted to move over the graduations provided at the edge of the table. The mirror is provided upon its face with a vertically disposed line which is in alignment with the axis of the shaft. Spaced inclined mirrors are located in the casing and vertically disposed threads are located in the casing one at each side thereof and at the ends of the space between the interiorly located mirrors.

In the accompanying drawings y Figure 1 is a side elevation of the surveying instrument.

Figure 2 is a similar view looking at the side opposite to that which is shown in Figure 1. Y

Figure 3 is a top plan view of the surveying instrument.

Figure 4 is a transverse sectional view of the surveying instrument.

Figure 5 is a detailed fragmentary sectional view of the surveying instrument and showing parts in side elevation.

Figure 6 is a diagrammatic plan view indicating a mode of using the instrument.

As illustrated in the accompanying drawing, the surveying instrument comprisesa casingi whichiis provided at one sidewith a sight openingQ and atLits :opposite side withwa sight opening, *vertically disposed threadlines 4 and 5 `are disposed across the openings 2 and 3 .respectively and are lo cated exactly midway between the side walls of thecasingl. A spirit level 6 ismounted ulponthe base` of.` the casing 1 atthe flower e ge of thesight opening 2. It-bis to be understood that the casingl `may be mount ed upon a tripod structure (not shown.) or any ether. suitable. means lasfor instance a rod 7 may be Aprovided forA supporting the said casing. .i .If desired,v the casing maybe held in the hand of the operator` A circular, table `r3 is mounted upon the top side of the casing land isprovidedvaround its periphery with a series of graduations 9; l. A vertically disposed shaft 10 is journaled at the center ofthe table8 `andcarries at its upperenda frame 11 in whichislocatedya vertically disposed mirror 12. The mirror 12 is provided at a point midway between its ends and in alignment with the axis of the shaft 8 with a hair line 13. The frame 11 is provided at one end with an arcuate arm 14 having upon its outer side a series yof graduations 15 which are adapted to move over the graduations 9 as the frame and mirror are turned upon the tableand as will be explained hereinafter.y A beveled gear wheel 16 is located interiorly of the casing 1 and is fixed to the'shaft 16 by means of a sleeve 17 which is carried at the center of the said gear wheel and which is provided with a slot 18 receiving a pin 19 which is carried by the shaft 10. A horizontally disl posed shaft 20 is journaled in the casing 1 and one end of the said shaft 2O projects beyond the side of the casing and is provided with a knob 21. A beveled pinion 22 is carried at the inner end of the shaft 20 and meshes with the gear wheel 16 hereinbefore described. It is apparent that b turning the shaft 2() and by using the kno 21 that rotary movement will be transmitted to the shaft 10 through the intermeshing4 pinion and gear wheel 22 and 16 and the frame 11 and the mirror 12 may be turned above the upper surface of the table 8. A compass 23 is embedded in the upper surface of the table 8 and is disposed at one side of the shaft 10 and the center of the table 8.

In use" the threads 4 and 5 are aligned Y with thel eye -(indicated at29 in. Figure 6) and with an'object y30 as 'fori instance a house as shown in the said figure. ,Thew

mirror 12 is then turned so thatthe reflection of a tree 31 is brought upon' the line 13 of the said mirror and visible by the eye 29.

Y computing the graduations, the magnitude of the angle may be determined and by the known methods of triangulation it may be definitely determined as to therdistance between the objects andqalso'the distance of the objects from the Aeye of the observer.'

.Having thus described the invention, whatIclaim is:-

1. A measuring instrument comprising a casing. provided at its-opposite sides vwith sight openings and having vertically disposed threads extending across the openings at points midway between the endsof the openings, inclined spaced `mirrors located in the-casing between the sight openings, a tabley mounted upon the casing and provided with a series of graduations, a vertically disposed vmirror mounted for turning movenient at v4thecenter of the table and having a line disposed in alignment with the center of the table, said mirror carrying a series of graduations `adapted to move over the first mentioned graduations and means for turning the mirror.

2. A measuring instrument comprising a casing provided at its opposite sidesfwith sight openings and having threads disposed transverselyk across said. openings, inclined spaced mirrors located in the casing between the openings, a spirit level carried by the casing, a table mounted upon the casing, a compass carried by the table, the table being'provided with a series of graduations, a mirror mounted for turning movement at the center of the table and having a series of graduations adapted to be moved over the first mentioned series of graduations7 means for turning the mirror and a hair line carried by the ymirror and disposed vertically in alignment with the center of the table. f f t 'In testimony whereofv I affix'my signature.

JOHN vENETTA. 

